Biomarker

Omics

Analytical Method

Sample Source

Marker type

Regulation (ratio)

Ref.

Free glycerol
Glycerylisoprene acetals
Monopalmitin
Monostearin
1,3-Dipalmitin
1-Stearin-3-palmitin
1,3-Distearin
Tristearin

Lipidomic

ESI-QhQ/MS

Tear (Rabbit)

Dry eye

Up (1.6)
Up (2.4-2.5)

Up (1.5)
Up (1.6)
Up (1.5)
Up (1.4)
Up (1.4)
Up (1.4)

[47]

Pyrophosphate sphingomyelin
Phosphatidylserine

Lipidomic

MALDI-TOF/MS

Tear (Rabbit)

Dry eye

Up (ND)

Up (ND)

[48]

Polar and neural lipids (m/z data only)

Lipidomic

HPLC/MS

Meibum (Human)

Age-related dry eye

Various changes (ND)

[49]

Diadenosine polyphosphates

Metabonomic

HPLC (Shirmer tear collection)

Tear (Human)

Dry eye

Up (100–345; with low tear secretion subjects)

[50]

Tear osmolarity

–

Osmometer

Tear (Human)

Dry eye

Up (ND)

[51]
Ratio: (diseased eye)/(normal eye) ND: not determined, ESI-QhQ/MS: electrospray ionization-quadrupole-hexapole-quadrupole/mass spectrometry, MALDI-TOF: matrix assisted laser desorption ionizationtime of flight, HPLC: high-performance liquid chromatography
Table 4: Tear- and meibum-associated potential lipid and non-lipid/protein biomarkers tentatively identified for dry eye in animal models and human subpopulations [28].